Want to help the poor? Start by taking money out of their hands. More specifically, cash — coins and paper bills are the silent enemy of the poor, with costs often out of proportion with their day-to-day convenience.

U.S. negotiators are heading into a second day of what have been dubbed “serious and substantial” talks with North Korean officials. Yet amid all the discussion of how the U.S. will attempt to work with Kim Jong Un, there has …